Releasing device for drive-wheel brakes



No. 618,473.' Patented 1an. 3|, |899. w. o. PELHAM.

RELEASING DEVICE FOR DRIVE WHEEL BRAKES.

(Application med Apr. 7. 189s.) (No Model.) 2 Sheets-Sheet l.

f/. M M w/ We I f N e I A mnIIIWIM I i vll No. 6|s,47s Patented 1an. 3|,|899.

w. o. PELHAM., RELEASING DEVICE EUR DRIVE WHEEL BRAKES.

(Application'led Apr. 7, 1898.)

(N0 Modem 2 sheets-sheet 2.

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Nrrnn STATES ATENT Fries.'

W ALTER O. PELHAM, OF ST. LOUIS, MISSOURI.

SPECIFICATION forming part of Letters Patent No. 618,478, dated January31, 1899.

Application filed April 7, 1898.

Be it known that I, WALTER O. PELHAM, a citizen of the United States,residing at the city of St. Louis, in the State of Missouri, haveinvented a certain new and useful Improvement in Releasing Devices forDrive- Wheel Brakes, of which the following is a full, clear, and exactdescription, reference being had to the accompanying drawings, formingpart of this specification.

My present invention relates to an improvement on the device of the samecharacter as that set forth in Letters Patent of the United States No.586,455, granted to me July 13, 1897. Y

In'this improvement, as in the one shown and described in the patentmentioned, the object is to produce an eifective release device forlocomotive drive wheel brakes, through the medium of which the saidbrakes are instantly released when fluid-pressure is admitted to thesteam-chest of the engine-cylinder.

The invention consists in features of novelty hereinafter fullydescribed, and pointed out in the claims.

Figure I is a vertical sectional View taken on the line I I, Fig. II,through my improved device. Fig. II is a vertical sectional view takenon the line II II, Fig. I, a portion of the pipe that conveys the backpressure vfrom the engine-cylinder beingshown in elevation. Fig. III isa side view of a locomotive with my improvement applied thereto.

Referring to Fig. III, 1 designates the locomotive drive-wheels, and 2the brakes designed to operate against said wheels. The brakes arearranged in common manner and are connected to the piston-rod of thebrakecylinder 3.

4 is one section of the brake-pipe connected to the cylinder 3. l

5 is the auxiliary cylinder, and G the triple valve connected therewith.

7 is a second section of the brake-pipe connecting the triple valve andthe exhaust de-y f vice 8.

The brake-pipe section 4 also communicates with the exhaust device 8, asseen in Figs. II and III. I

9 designates a pipe communicating with the steam-chest 10 of theengine-cylinder and with the exhaust device at its lower end.

Serial No. 676,835. (No model.)

This pipe is provided with a suitable draincock 11. The connections andpurpose of the pipe 9 between the cylinder steam-chest and the exhaustdevice are similar to that set forth in my patent herein referred to.

12 designates a lower-valve chamber of the Vexhaust device 8, with whichchamber the pipe 9 communicates.

13 is a piston-valve located in said chamber and having anupwardly-extending stem 14, that operates in a guide-partition 15. Thelower end of the valve-chamber is closed by a cap 16, to which the pipe9 is connected. The v alve 13 is formed with a cavity 13a and anaperture 13", that opens into the cavity 13a, the said opening beingsurrounded by an annular rim 13, that enables the production of a wellaround said rim for a purpose to be presently explained. The lower faceof the valve 13 is formed with an annular valveseat 13d, surrounding theaperture 13b at the entrance into said valve-chamber 12 from the pipe 9.This valve-seat 13d holds the outer lower face of the valve 13 away fromcontact with the cap 16, thereby leaving a recess around said valve-seat13d when the valve is in its lowermost position, into which sedimententering'the valve-chamber may deposit, so that it will not interferewith the proper seating of the valve against the cap 1G when such valveis in its lowermost position. The well surrounding the rim 13C alsoproduces a receptacle for the deposit of sediment carried through theopening 13b into the cavity 13.

To further provide against sediment or fory eign matter interfering withthe operation of the piston-valve 13, Iform a groove 13f in theperiphery of said valve, into which such matter may enter, if it passesthe vbase of the valve. The upper face of the valve 13 is provided witha ground-seat 13e, that contacts with a ground-seat 12a in thevalve-chamber when the valve 13 is in its uppermost position.

17 designates a passage-way leading from the valve-chamber 12 from abovethe valve 13 through a horn 12b into a pipe 18. This passage-wayprovides for the exit of any leakage of steam that may escape past thepistonvalve 13, and also dispenses with vacuum above the piston-valvewhen said valve falls to its lower seat.

19 designates an upper valve-chamber, the

upper end of which is closed by a cap 20. The

fluid-conveying brake-pipes 4: and 7 are connected to this uppervalve-chamber at its lowernnost portion, as is clearly illustrated inFig. Il. Within the valve-chamber 19 is a valve-receiving cup 21,extending upwardly to a considerable height above the base of thevalve-chamber 19. This valve-receiving cup is provided near its upperend with a valve-seat 22 and at the lower end with a valve-seat 23.

21 is a passage-way leading from the valvereceiving cup into apassage-way 25, that communicates through the horn 12b with the pipe 1Sfor the exhaust of pressure medium iiowing through the valve-cup 21 pastthe valves therein when such valves are opened in the manner to behereinafter explained. The horn 12 and pipe 18, with the passage-waysleading through said horn, provide a means for the vent of .pressuremedium without exposing such passage-ways for the entrance of foreignmatter that might otherwise enter the exhaust device and render theseating of the valves therein imperfect by clogging the valves or theirseats.

26 designates an upper valve located in the valve-receiving cup 21 andarranged to seat against the valve-seat 22 therein. This valve 26 isprovided with guide-wings 27, depending therefrom and extending from astem 27a, and it is normally held to its seat by a spring 28, arrangedbetween the valve and the cap 2O of the upper valve-chamber.

29 designates an intermediate valve arranged to seat against thevalve-seat 23 and provided with depending guide-wings 30, carried by thevalve-stem 31. The valve 29 is surmounted by a stem 32, the end of whichenters a socket 271 (see Fig. I) in the stem of the valve 26 to providea guide to maintain the valves 2G and 29 in proper relation to eachother. The valve-receiving cup 21 extends to a considerable distanceabove the points of connection of the pipes 4i and 7 to the valvechamber19, and any sediment entering the valve-chamber 19 falls to the bottomof the valve-chamber, which forms a well surrounding the valve-receivingcup, and the sediment is thereby kept from entering the valve-receivingcup 21 and preventing the proper seating of the valves 26 and 29therein.

The features of improvement herein relate to the construction of theexhaust device, in which the prime features are the employment of thetwo upper valves 26 and 29 instead of the single valve shown in mypatent heretofore mentioned, whereby 1 am enabled to obtain greatersurety in the proper operation of the device, for in the event of one ofthe valves failing to seat properly the other valve going to its seatprevents the passage of any leakage that may have escaped past the firstvalve.

A further material improvement lies in the peculiar construction of theparts whereby the entrance of sediment into the valve device isprevented by reason of the construction of the parts from interferingwith the proper working of the valves; also, the horn 12b and pipe 18,through which the leakage and exhaust escape from the exhaust device.

The operation of this improvement is substantially the same as thatdescribed in the patent to which I have herein referred. On reversingthe engine or on admitting steam to the chest of the engine-cylinderafter it has beenturned off when the brakes are applied the backpressure from the chest of the engine-cylinder is conveyed through thepipe 9 to the exhaust device and operates against the piston-valve 13,raising said valve from the position shown in Fig. I to that shown inFig. III, and carries the valves 26 and 29 in an upward direction. Onthe unseating of the valves 26 and 29 the fluid-pressure medium in thebrakepipe section 7 and the brake-cylinder 3 enters the uppervalvechamber 19, fiows past the valves 26 and 29, and exhausts throughthe passage-way 25 through the horn 12b into the pipe 1S, and anyleakage of steam past the piston-valve 13 finds an outlet into the pipe18 through' the passage-way 17 of the horn 12. By this means thepressure mediumis exhausted from the brake-cylinder 3, thereby instantlyreleasing the brakes from the drive-wheels 1.

I claim as my invention- 1. In a releasing device for the brakes ofdrive-wheels, the combination with the brakepipe, of an exhaust devicelocated in said brake-pipe, and a pipe providing communication betweensaid exhaust device, and the steam-chest of the engine-cylinder; saidexhaust device having an outlet for the escape of pressure fluid, andcontaining an upper valve, a lower intermediate valve, adapted, whenmoved, to open said upper valve, and a lower valve arranged to move saidintermediate valve, substantially as set forth.

2. In a releasing device for brakes of drivewheels, the combination withthe brake-pipe, of an exhaust device locatedV in said brakepipe, and apipe providing communication between said exhaust device and thesteamchest of the engine-cylinder said exhaust device containing a lowerpiston-valve, an upper valve, a lower intermediate valve, and a hornextending from said exhaust device having passage-ways for the escape ofpressure medium flowing past said valves, substantially as and for thepurpose set forth.

3. In a releasing device for the brakes of d rive-wheels, thecombination with the brakepipe, of an exhaust device located in saidbrake-pipe, and a pipe providing communication between said exhaustdevice and the steam-chest of the engine-cylinder; said exhaust devicecomprising a lower valve-chamber, a piston-valve in said chamber, anupper valve-chamber, a valve-receiving cup in said upper chamber, anupper valve and a lower intermediate valve in said cup, and a horn IOOIIO

having passage-ways for'the vent of pressure medium from saidvalve-chambers, substantially as described.

.4. In a releasing device for the brakes of drive-wheels, thecombination with the brakepipe, of an exhaust device located in saidbrake-pipe, and a pipe providing communication between said exhaustdevice and the steam-chest of the engine-cylinder; said exhaust having alower piston-valve, an upper valve, and a lower intermediate valve; saidpiston-valve being provided with a cavity and an opening leading intosaid cavity, and a rim in said cavity, substantially as described.

5. In a releasing device for the brakes of drive-wheels, the combinationwith the brakepipe, of an exhaust device located in said pipe, and apipe providing communication between said exhaust device and thesteamchest of the engine-cylinder; said exhaust device containing anupper valve, a lowerintermediate valve adaptedgvhen moved, to.

open said upper valve, and a lower valve arranged to move saidintermediate valve, and

WALTER O. PELHAM.;

In presence of@ E. S. KNIGHT, STANLEY STONER

